Maybe he seems like a good prospect because he's got a good salary and he's building a house.
But the house is not finished, he can't afford to finish it, he's got massive debt, and even if he finished it somehow - won't the creditors be after it to sell it to settle debts?
It wouldn't be in any part yours unless he married you - and even then, it's highly unlikely there'd be much value in it , with him being heavily in debt and seeming to have a habit of running up big debt repeatedly.
Then there's the salary, how much do you actually see of that? It sounds more like he lives off you.
Your best chance of seeing any of it is child maintenance .. if he doesn't scam his way out of proper assessment.
The poster who wondered what exactly he's doing, aside from drink, with his money that he's in a good salary but has big debts, raised a good point. It's weird.
Even if you got married, you were able to stay in that house (unlikely) and you had a claim on it (though you would also possibly be liable for his debts) .. he still drinks every day, doesn't pull his weight, and has threatened to hit you/could become physically abusive too.
But I don't think he's going to let you get at any of his money really - not that there ever seems to be any with his debt issues.